Speaking to Constituent Assembly members at parliamentary party office here on Friday, Koirala said he had rejected Prime Minister Prachanda's proposal to join the government.
"Nepali Congress will not join the government until the past agreements are implemented and seized property by Maoists during the people's war is returned to the rightful owners, Koirala added.
Meanwhile, the Nepali Congress (NC) Parliamentary Party (PP) decided to raise strong voices against the Maoist-led coalition in the Parliament for not translating past pacts and understandings into practice.
In its meeting, Koirala directed its lawmakers to speak up in the Parliament against the ongoing violence, killings and anarchy unleashed by Maoists cadres.
According to Kantipur, Koirala directed the lawmakers to raise the issues strongly so as to disseminate positive messages at the national and international arena. He also suggested to form a taskforce for the identification of crucial issues to be raised in the House.
Referring to the recent killing of a UML cadre in Butwal, deteriorating law and order situation and attacks against media, Koirala said, "Knowingly or unknowingly, the Maoists have attacked the independent judiciary and national army. They are heading towards dictatorial regime," he claimed. (ANI)